Method of protecting seeds using-short



United States Patent 2,740,744 p METHOD oF PRGTECTING sE os'UsrNG-srrenr ALKYL CHAIN AR'IMONIUM'HALIDES Walter W. Abramitis, Downers Grove, 111., Walter C. OKane, Durham, N. H., and James Hal-wood, Western Springs, 111., assignors to Armour and Company, Chicago, 111., a corporation of Illinois No Drawing. Application August 2, 1952, Serial No. 302,404 11 Claims. (Cl. 167-38) Tliis invention relates to seed protectants, and more particularly to the use of tetraalkylammonium salts as seed protectants.

Seeds and young plants are subject to attack by certain soil-inhabiting organisms generally designated as fungi. Certain of these harmful fungi in the soil are more specifically designated as damping off organisms and as post damping off organisms. Thedamping off organisms attack the seed or seedling, while the post damping off organisms attack the emerged plant near the top of the soil. The problem of effectively combating these organisms is both serious and of long standing. Chemical treatment of seeds prior to planting has proven of considerable benefit, but tlie compositions heretofore used for this purpose leave much to be desired both from the standpoint of effectiveness and cost of treatment. Therefore, the search for better seed protectant compositions'has actively continued.

It is therefore a general object of this invention to provide seed protectants whichare more effective and less expensive than those which have heretofore been known. It is a further object of this invention to provide seed protectant compositions which function in a novel manner to protect the seeds. It is a still further object of this invention to provide a method for treating seeds with the novel protectant compositions ofthis invention. Further objects and advantages will become apparent as the specification proceeds.

, This invention is based in part on the discovery that lower tetraalkylammonium salts are capable of protecting seeds against harmful soil fungi. Further discoveries underlying the present invention will subsequently be discussed.

The process of the present invention is applicable to a wide variety of seeds. Of course, the seeds must be viable or capable of germination. However, it will be understood that in a group of seeds treated, that a certain percentage will not be capable of germination, and that the treatment of such mixtures of viable and non-viable seeds is intended to be included within the scope of this invention. The method of this invention is particularly desirable for the protection of vegetable seeds, flower seeds, and grain seeds. Among the specific types of seeds which have been found to be effectively protected by the method of this invention .are the following: celery, tomato, lettuce, millet, pea, cucumber, alfalfa, cabbage, beet, cantaloupe, carrot, clover, onion, radish, spinach, grass, tobacco, turnip, lima bean and corn. In general, the germination and emergence of seeds, such as those listed above, is greatly improved by the treating method of this invention as compared to the germination and emergence of untreated seeds. Furthermore, as compared with standard commercial seed protectants such as tetrachloro-p-benzoquinone, the seed protectants' of this invention are of at least comparable effectiveness even though employed in much smaller quantities. A great majority of. the seeds tested were found to be much more effectively protected by the compositions of this invention even though up to four times as much of the commercial seed protectant was employed as the compounds of the present invention.

As indicated above, this invention is based in part on the discovery that the lower tetraalkylammonium salts possess seed protectant properties. By lower is meant thateach of the alkyl groups contain less than 9 carbon atoms. salts for use as seed protectants should contain less than 5 carbon atoms in each of their alkyl groups.

alkylarnmonium ion.

ments in addition to the members of the halogen family; For example, phosphate, sulfate, and nitrate salts can be: employed. In addition, organic anions may be used. In particular, fatty acid salts are desirable, including lower fatty acid salts such as acetate salts and higher fatty acid salts such as stearate salts. Specific preferred salts are chloride and bromide salts, and specific preferred compounds are tetramethylammonium chloride, tetramethylammonium bromide, trimethylethylammonium chloride, and trimethylethylammonium bromide.

Various techniques can be employed for treatingseeds with the seed protectant compounds of this invention. One excellent method of treatment is to dissolve the compounds in a liquid carrier, and then contact the seeds with the solution thus formed. While aqueous treating solutions are preferred, other solvents can be employedwhich are not harmful to the seeds, such as the lower alcohols (ethanol) and the lower ketones (acetone). The concentration of the treating solution is not particularly critical and can be varied within rather wide limits. For example, substantially saturated treating solutions might be employed. When aqueous solutions are employed at least 1% concentrations, and preferably at least 2.5% concentrations are desirable. Excellent results are obtained with concentrations from about 5 to 10%, although much higher concentrations up to the limit of the solubili-I ty of the compounds can be employed. However, theredoes not appear to be any particular advantage in using;

very high concentrations.

The technique of treating the seeds with aqueous solu-- tions of the compounds is very simple, since only a'shortj contact time is required. In fact, satisfactory results can be obtained by merely dipping the seeds in the treating solution, and immediately thereafter removing the seeds therefrom. In other Words, depending somewhat on the concentration of the solution, effective protection of the seeds may be obtained with contact times as short as 10 to 20 seconds, although contact times of around 2 to 3 minutes are generally desirable to provide an assurance that maximum protection has been obtained. However, considerably longer contact times are not harmful, and can be used if desired. The temperature of the treatment has not been found to be critical, and treatments at room temperature (20 to 25 C.) are entirely satisfactory. After the seeds have been immersed in the treating solution, it is generally desirable to drain and dry the seeds. Depending somewhat on the concentration of the treating solution and the absorptiveness of the seeds, a film or coating of the protectant compounds will gen: erally be visible on the outside of the treated and dried seeds.

Another excellent method of applying the protectant compounds is by distributing the solid compounds in a solid carrier and then contacting a mixture of the carrier and the protectant compounds with the seeds. Fairly Preferably, however, the tetraalkylammoniumv While thehalide salts are preferred, many other salts can be em-- ployed. The seed protectant properties of the compositions of this invention are believed to reside primarily in: the cationic portion of the molecule, that is, in the tetra-- The anionic portion of the molecule: is of lesser importance, except that in order to take ad-- vantage of the seed protectant properties of'the cationic: portion of the molecule, it is necessary that the cationic: portion be relatively non-toxic to the seeds treated. A. large number of inorganic cations fulfill these require good results can be obtained by directly contacting the seeds with the undiluted compounds. However, since a large number of the lower tetraalkylammonium salts are very hygroscopic and tend to be sticky or gummy, it is increase the germination rate of untreated seeds. The desired effect can be obtained by tumbling the seeds either mechanically or by hand so that the mass of seeds is rotated or otherwise agitated in such a manner as to preferable to first mix them with a diluent or carrier, 5 cause the seeds to roll over or rub against each other. which facilitates the distribution of the protectant com- Preferably, this tumbling action should not be so violent pound over and throughout the seeds. Standard inert as to break the seed coats or otherwise damage the seeds. carrier materials for insecticides, fungicides, etc. can be A gentle tumbling of from 1 to 2 hours has been found to used for this purpose. For example, talc, clays, etc. may give the desired result, although some benefit is achieved be used. The concentration of the protectant compounds by tumbling times as short as 10 minutes. in the carrier-protectant composition is not critical. For The explanation for the value of the compositions of example, concentrations ranging from 10 to 50% are satthe compounds of this invention as seed protectants is isfactory. For practical purposes, concentrations of not understood. The generally accepted basis for the around 25% have been found to give excellent results. selection of a seed protectant composition relates to the Various techniques can be employed to promote an fungicidal properties of the composition. In fact most, intimate contact between the solid seed protectants either if not all, of the seed protectants in commercial use have alone or in admixture with a solid carrier. Various stand marked fungicidal properties against soil-inhabiting orard commercial contact apparatuses can be used within ganisms of the type which are known to attack seeds, which the seeds are agitated or tumbled in contact with seedlings, and young plants. However, the lower tetrathe protectant compositions. Generally, 5 to 10 minutes alkylammonium salts were not previously known to possess of tumbling or agitation is suflicient to obtain the maxifungicidal properties, and in fact in vitro fungicidal tests mum protection. have failed to disclose fungicidal properties. It may be Some salts of the tetraalkylarnmonium halides are rethat the lower tetraalkylammonium salts possess in vivo latively non-sticky and free flowing. Therefore, these fungicidal properties, but this has not yet been established. salts are particularly desirable when it is desired to treat It is also possible that the protectant compounds of this the seeds with a solid protectant composition without eminvention function indirectly by stimulating or invigoratploying a diluent or a carrier. In particular, the higher ing the seeds in some way so that their natural resistance saturated fatty acid salts have this desirable property. to fungicidal attack is increased. Specifically desirable salts in this regard are palmitate For the purpose of more clearly illustrating the present and stearate salts, such as trimethylethylammonium palmiinvention, it is desired to set out the following illustrative tate or stearate, and tetramethylammonium palmitate or examples. stearate. Example I i i been foulnd i g fg ji i i fig Tests were conducted to determine the effectiveness of Sa s i323? igf g i C 2:; ibe d as tetramethylammonium bromide, tetramethylammonium 5: 1a f These bmtonite c0? chloride, trimethyle'thylammonium chloride and tetra a i g g g f de'sirable m of bein ethylammonium bromide as seed protectants. Tests were g :mIiStick or free flowin gelieved i conducted so as to obtain a comparison not only between ha g th r definable IO ert z romotim the these compounds and untreated seeds, but also between 3: gsiticpspfopheysmedg and 6 2 40 these compounds and seeds treated with a standard com- 0 th ease 60am) seed: y mercial seed protectant, viz. tetrachloro-p-benzoquinone. 3 Hg 6 The chemicals were formulated into 25% dusts using After the contacting of the seeds with the solid piotectant co'n ositions it is desirable to remove the excess Pyrax ABB as a dlluent' Molstened Seeds were rolled p in each dust until throughly coated, and then planted in protectant composition from the treated mass of seeds.

unsterile greenhouse soil In flat boxes. Observation of It has been found that after treating the seeds either 4; seedling emergence was made when emergence was comwith the solid protectant composiuons or with solutions plate The Chemicals were coded as follow? thereof that it is desirable to tumble the seeds for a short interval of time. It has been discovered that by tumbling DlTetramethylammonium bromide the seeds for a short period of time that a considerably D2-Tetramethylammonium chloride higher germination rate is achieved than with treated, D3Trimethylethylammonium chloride untumbled seeds. The reasons for the value of the tum- D4--Tetraethylammonium bromide bling step are not fully understood. However, it is Sd.86% tetrachloro-p-benzoquinone known that similar tumbling procedures do not noticeably Ck.-Check (untreated) 8 Days End of Period Code No. Percent Crop Variet Net N t Cone. y Percent 535 9 3 Percent Percent g g g Perc ent Emerged D Healthy Emerged D Healthy Plants Plants 25.0 66.0 0.0 66.0 25.0 66.0 6.0 60.0 25.0 ]Cel0ly Giant Pas- Not Re- Not Re- Not Re- 36.0 0.0 36.0 100. 0 cal. corded. corded corded. 62. 0 2. 0 60. 0 0.0 4.0 0.0 4.0 25.0 02.0 2.0 90.0 25.0 78.0 0.0 78.0 25.0 }Tomato Pritchard... 72.0 2.0 70.0 100. 0 74. 0 2. 0 72. 0 0.0 82.0 0.0 82.0 25.0 76.0 2.0 74.0 25.0 78.0 2.0 76.0 25.0 }Lettuce Iceberg 72.0 0.0 72.0 100. 0 72. 0 2. 0 70. 0 0.0 30.0 0.0 30.0 25.0 76.0 0.0 76.0 23-2 8-8 at Millct Japanese Not Be- Not Re- Not Re- 3g: 8 corded. corded corded. Z3: 8 8: 8 g 0.0 78.0 0.0 78.0

1 Damping oft.

jars. The protectant compounds were added to these jars either as 1 ml. of a 10% water solution thereof, or as .07 gram of the compounds plus 1 ml. of water. The

ard commercial seed protectant was added in a compar able amount as a dust and as a slurry. Immediately after introducing the chemicals, the jars were placed on a ball Thereafter, the seeds were dried in the jars for 24 hours. After drying, each jar was placed in a tumbling machine with the jar cap replaced with a wire mesh cap and tumbled for 2 hours.

P c t nt Plants The chemicals Net Percent Plants 5 check was made with 1 ml. of water only, and the'stan d 10 mill and rotated for 5 minutes.

Percent of Emerged Healthy A duplicate series was prepared; rotatedon the ball'rnill,"

were planted in moist infected greenhouse soil, and ob-- served for seedling emergence at 12 days. were coded as follows:

D1--Tetramethylammonium bromide D2-Tetramethylammonium chloride Emerged Healthy 100 seeds Percent Emergence The The chemicals Variety Grimm.

Hales Best lAlt'altm }Beet Mangel., }Cantaloupe Percent Cone.

Example 111 No. Seeds t m 0 910732000300040 m0 e D P t 6 000000000000000 r 33115 7 WWW 88776QU5 MM%%%W r e mu iii .l t m m m r W H n H w 5 New Y M 0 b a n n v.0 V n M H aL a 2 D L E u h d M a d MW n v w S a n 1 C C R O O 0 0 O 5 1 1 iii Substantially the same procedure was followed'as in Example I in testing the following chemicals.

Observations of seedling emergence were Code No.

were treated by atomizing water on them with a small spray nozzle and then adding the dust to thoroughly coat the seeds.

made when emergency was complete.

were coded as follows:

Dl-Tetramethylammonium bromide D2--Tetramethylammonium chloride D3Trimethylethylammonium chloride Sd.86% tetrachloro-p benzoquinone Ck.Untreated check Percent Gone.

Beet-Multiple seeds which produce many seedlings-aetual numbers and not percentages given.

The procedures of Examples I and II were followed 40 for 5 minutes, and dried but not tumbled- All Said-Sf Code No.

in further testing of the protectant compounds. chemicals employed in these tests were coded as follows:

D3Trimethylethylammonium chloride Sd.86% tetrachloro-p-benzoquinone Ck.Untreated check D1Tetramethylammonmium bromide D2-Tetramethylammonium chloride D3 Trimethylethylammonium chloride Sd.-86% tetrachloro-p-benzoquinone Sd.-Sl.Aqueous slurry tetrachloro-p-benzoquinone; 75 Ck.Check Example IV Twenty-nine grams of pea seeds (approximately 106 to 107 seeds), were weighed in each of nine seed-treating Average Percent Percent Net Per- Materlal Percent Concentration Tumbled Fmer a Healthy cent g Plants lielaltlgy an S 1.0 ml. of 10.0% solution Not tumbled 60 58 64 clo 72 70 Tumbled. as as 70 do 74 74 Not tumbled" 80 76 75 7 a a l a a i 72 6g 58 5 a a a i 8 a 83 v 28 Sd. (Dry) fig g: r a s i 30 28 i 38 Sd. S1

7s 7s 65 52 52 8 Ok 12 10 i 9 10 8 10 s 1 D 3 22 20 i 18 54 54 51 While in the foregoing specification specific embodiments of the present invention have been set forth in considerable detail for the purpose of illustration, it will be apparent to those skilled in the art that many of the details set forth can be varied widely without departing from the spirit of the invention.

We claim:

1. In a method of increasing the resistance of seeds to attack by soil-inhabiting organisms, the step of treating seeds with a composition containing as its essential active ingredient a tetraalkylamrnonium halide having less than 5 carbon atoms in each alkyl group.

2. In a method of increasing the resistance of seeds to attack by soil-inhabiting organisms, the step of contacting seeds with an aqueous solution containing as its essential active ingredient a tetraalkylammonium halide having less than 5 carbon atoms in each alkyl group.

3. In a method of increasing the resistance of seeds to attack by soil-inhabiting organisms, the step of treating seeds with a composition containing as its essential active ingredient a tetraalkylammonium halide in admixture with a solid carrier, said halide having less than 5 carbon atoms in each alkyl group.

4. In a method of increasing the resistance of seeds to attack by soil-inhabiting organisms, the step of treating seeds with a composition containing as its essential active ingredient a tetraalkylammonium salt having less than 5 carbon atoms in each alkyl group, said salt being selected from the group consisting of chloride salts and bromide salts.

5. In a method of increasing the resistance of seeds to attack by soil-inhabiting organisms, the step of treating seeds with a composition containing as its essential active ingredient a compound selected from the group consisting of tetramethylammonium halides and trimethylethylammonium halides.

6. In a method of increasing the resistance of seeds to attack by soil-inhabiting organisms, the step of treating seeds with a composition containing as its essential active ingredient a compound selected from the group consisting of tetramethylammonium chloride, tetramethylammonium bromide, trimethylethylammonium chloride and trimethylethylammonium bromide.

7. In a method of increasing the resistance of seeds to attack by soil-inhabiting organisms, the step of treating seeds with a composition containing as its essential active ingredient tetramethylammonium chloride.

8. In a method of increasing the resistance of seeds to attack by soil-inhabiting organisms, the step of treating seeds with a composition containing as its essential active ingredient trimethylethylammonium chloride.

9. In a method of increasing the resistance of seeds to attack by soil-inhabiting organisms, the steps of treating seeds with a composition containing as its essential active ingredient a tetraalkylammonium halide having less than 5 carbon atoms in each alkyl group, and tumbling said treated seeds.

10. In a method of increasing the resistance of seeds to attack by soil-inhabiting organisms, the steps of contacting seeds with an aqueous solution containing as its essential active ingredient a tetraalkylamrnonium halide having less than 5 carbon atoms in each alkyl group, and tumbling said seeds.

11. In a method of increasing the resistance of seeds to attack by soil-inhabiting organisms, the step of contacting seeds with a tetramethylammonium halide dispersed in a bentonite clay, said halide having less than 5 carbon atoms in each alkyl group, said halide constituting the essential active ingredient in the composition.

References Cited in the file of this patent UNITED STATES PATENTS 2,309,592 Hueter Jan. 26, 1943 2,494,941 G011 Jan. 17, 1950 2,519,924 Nowak Aug. 22, 1950 2,541,248 Hibbs Feb. 13, 1951 

1. IN A METHOD OF INCREASING THE RESISTANCE OF SEEDS TO ATTACK BY SOIL-INHABITING ORGANISMS, THE STEP OF TREATING SEEDS WITH A COMPOSITION CONTAINING AS ITS ESSENTIAL ACTIVE INGREDIENT A TETRAALKYLAMMONIUM HALIDE HAVING LESS THAN 5 CARBON ATOMS IN EACH ALKYL GROUP. 